The invention concerns a light, in particular a splash water-protected wall light or ceiling light, for receiving at least one elongate gas discharge lamp. The light comprises a housing that can be assembled in closed form from an at least translucent base part that is stationarily mountable and holds electrical devices and an at least translucent dome part, wherein the base part and the dome part are produced by injection moulding from the same batches of thermoplastic synthetic material in a common mould that is substantially symmetrically designed relative to the injection process. The base part and dome part overlap along circumferentially extending rims provided on both parts, of which one rim is configured as an insertion rim and the other rim is configured as a U-shaped receptacle for the insertion rim. The invention also concerns a method in which the top part and the bottom part are produced simultaneously in parallel cavities of an injection moulding device by a common injection piston and are demoulded after solidification. Such a light and method are disclosed in German patent application DE103 33 980 A1. Lights of this kind that are primarily produced in large-scale production as mass-market products and accordingly are subject with regard to their manufacture and to the material to great cost pressure, can be generally produced by injection moulding from thermoplastic synthetic material, in particular polypropylene. Transparent or at least translucent synthetic materials as they are to be used for light emission of gas discharge lamps and similar elongate lamps however present significant difficulties as a result of their great thermal expansion that call into question proper fit and connection of the housing parts and in particular also the seal-tight connection between both.
For the best possible adaptation of materials of top part and bottom part including the compensation of thermal expansion coefficients, it has already been provided according to the prior art to produce both housing parts simultaneously with a common injection piston or the like injection source in adjacently positioned cavities. Even though, specific measures are needed in order to ensure a seal-tight connection between bottom part and top part under all operating conditions and temperature conditions. However, such configuration must be adapted taking into account the particularities of the material, in the present case an injection-mouldable transparent or translucent thermoplastic synthetic material, and the possibilities of a substantially automated mass production.